Caprolactam heat tracing hot water circulating device

Abstract

The utility model provides a caprolactam heat tracing hot water circulating device which comprises a caprolactam heat tracing system, a steam source, a first circulating pump, a second circulating pump, a smoke hot water heat exchanger, a steam hot water heat exchanger, a first thermometer, a second thermometer, a steam regulating valve, a backflow regulating valve and a controller. Waste heat of a coal-fired flue is utilized in a caprolactam heat tracing system in chinlon polymerization production, and the waste heat is recycled by combining a steam heat exchange system, a high-low temperature hot water backflow adjusting system and a pressure stability adjusting system.

Description

TECHNICAL FIELD

[0001] The utility model relates to a caprolactam hot water circulation device. BACKGROUND

[0002] In the PA6 chip production process, the transmission of caprolactam in the workshop needs to be kept warm by hot water, and the temperature needs to be kept above 68 degrees to keep it in liquid state. The source of hot water is to use steam heat exchange into low-temperature desalted water in the plate heat exchanger, and a negative feedback control loop is used to keep the heated hot water at about 88 degrees, and then the hot water is used for caprolactam pipeline heating.

[0003] The steam in the plate heat exchanger belongs to secondary or tertiary energy in production, and there is energy efficiency loss in the energy conversion process, and there is energy waste. The existing system cannot reflect the load change in time, for example, the load change cannot be adjusted in advance, and there is a large lag. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is to provide a caprolactam hot water circulation device, which utilizes coal-fired flue gas waste heat in the caprolactam heating system in polyamide polymerization production, and recovers waste heat by combining a steam heat exchange system, a high-low temperature hot water reflux regulation system and a pressure stabilization regulation system.

[0005] The utility model is implemented as follows: a caprolactam hot water circulation device, comprising a caprolactam heating system and a steam source, comprising a first circulating pump, a second circulating pump, a flue gas hot water heat exchanger, a steam hot water heat exchanger, a first thermometer, a second thermometer, a steam regulating valve, a reflux regulating valve and a controller.

[0006] The caprolactam heating system is provided with a water inlet and a water outlet, the steam hot water heat exchanger is provided with a steam inlet, a steam outlet, a first hot water inlet and a first hot water outlet, the flue gas hot water heat exchanger is provided with a second hot water inlet and a second hot water outlet, the water outlet is connected to one end of the reflux regulating valve and the first hot water inlet of the steam hot water heat exchanger through the first circulating pump, and the water outlet is connected to the second hot water inlet of the flue gas hot water heat exchanger through the second circulating pump; the second hot water outlet of the flue gas hot water heat exchanger is connected to the first hot water inlet of the steam hot water heat exchanger.

[0007] The first hot water outlet and the other end of the reflux regulating valve are connected to the water inlet of the caprolactam heating system in parallel at point A; the steam source is connected to the steam inlet through the steam regulating valve; the first thermometer is arranged between the first hot water outlet and point A; and the second thermometer is arranged between the water inlet and point A.

[0008] The controller is electrically connected with the first temperature meter, the second temperature meter, the first circulating pump, the second circulating pump, the backflow regulating valve and the steam regulating valve respectively.

[0009] Further, a pressure transmitter is arranged between the A point and the water inlet, and the controller is electrically connected with the pressure transmitter.

[0010] The caprolactam heat tracing hot water circulating device is used for recycling waste heat in a caprolactam heat tracing system in the production of polyamide, and the waste heat is recycled by means of a steam heat exchange system, a high-low temperature hot water backflow regulating system and a pressure stabilizing regulating system. BRIEF DESCRIPTION OF DRAWINGS

[0011] The utility model makes further explanation in combination with the embodiments with reference to the drawings.

[0012] Figure 1 is a principle block diagram of the caprolactam heat tracing hot water circulating device. DETAILED DESCRIPTION

[0013] Please refer to Figure 1 The caprolactam heat tracing hot water circulating device comprises a caprolactam heat tracing system 101, a steam source 102, a first circulating pump 103, a second circulating pump 104, a flue gas hot water heat exchanger 105, a steam hot water heat exchanger 106, a first temperature meter 107, a second temperature meter 108, a steam regulating valve 109, a backflow regulating valve 110 and a controller (not shown in the figure), wherein the controller is a single-chip microcomputer or a computer, which can be purchased in the market.

[0014] The caprolactam heat tracing system 101 is provided with a water inlet 1011 and a water outlet 1012, the steam hot water heat exchanger 106 is provided with a steam inlet 1061, a steam outlet 1062, a first hot water inlet 1063 and a first hot water outlet 1064, the flue gas hot water heat exchanger 105 is provided with a second hot water inlet 1051 and a second hot water outlet 1052, the water outlet 1012 is connected with one end of the backflow regulating valve 110 and the first hot water inlet 1063 of the steam hot water heat exchanger 106 through the first circulating pump 103, the water outlet 1012 is connected to the second hot water inlet 1051 of the flue gas hot water heat exchanger 105 through the second circulating pump 104, and the second hot water outlet 1052 of the flue gas hot water heat exchanger 105 is connected to the first hot water inlet 1063 of the steam hot water heat exchanger 106.

[0015] The first hot water outlet 1064 is connected to the water inlet 1011 of the lactam heat tracing system 101 after being connected to the other end of the return flow regulating valve 110 at point A in parallel with the first hot water outlet 1064; the steam source 102 is connected to the steam inlet 1061 through the steam regulating valve 109; the first thermometer 107 is arranged between the first hot water outlet 1064 and point A; and the second thermometer 108 is arranged between the water inlet 1011 and point A.

[0016] The controller is electrically connected to the first thermometer 107, the second thermometer 108, the first circulating pump 103, the second circulating pump 104, the return flow regulating valve 110 and the steam regulating valve 109 respectively.

[0017] The desalted water in the lactam heat tracing system 101 is transported out and divided into two paths, one of which enters the steam hot water heat exchanger 106 for heating through the first circulating pump 103, and the other of which enters the flue gas hot water heat exchanger 105 for heating, the flue gas hot water heat exchanger 105 can use the waste heat (140-160℃) of the flue gas for heating, further recovering the wasted heat, and when the temperature is not enough, the steam hot water heat exchanger 106 can be used for heating again to ensure that the temperature of the desalted water is about 88℃; the temperature of the hot water from the steam hot water heat exchanger 106 is detected by the first thermometer 107, when the temperature is too high, the steam regulating valve 109 can be controlled by the controller to reduce the steam entering the steam hot water heat exchanger from the steam source 102, and when the temperature is too low, the steam supply can be increased; the desalted water from the return flow regulating valve 110 is mixed with the desalted water from the steam hot water heat exchanger 106, and then the temperature is detected by the second thermometer 108, if the temperature is too low, the return flow regulating valve 110 is controlled to reduce the amount of desalted water, and the supply of steam can be adjusted according to the detection temperature of the first thermometer 107.

[0018] In this embodiment, preferably, a pressure transmitter 111 is further arranged between the point A and the water inlet 1011, and the controller is electrically connected to the pressure transmitter 111; the pressure at the point A and the water inlet 1011 is detected by the pressure transmitter 111, and then the frequencies of the first circulating pump 103 and the second circulating pump 104 are adjusted to ensure the internal pressure of the entire device.

[0019] In the description of the utility model, it is understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0020] Although the specific embodiments of the utility model are described above, those skilled in the art should understand that the specific examples described by us are only illustrative, and are not used to limit the scope of the utility model, and equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the utility model should be covered within the scope of protection of the claims of the utility model.

Claims

1. A lactam heat assisted hot water circulation apparatus comprising a lactam heat assisted system and a source of steam, characterised in that: The first circulating pump, the second circulating pump, the flue gas hot water heat exchanger, the steam hot water heat exchanger, the first thermometer, the second thermometer, the steam regulating valve, the backflow regulating valve and the controller are included. The lactam heating system is provided with a water inlet and a water outlet, the steam hot water heat exchanger is provided with a steam inlet, a steam outlet, a first hot water inlet and a first hot water outlet, the flue gas hot water heat exchanger is provided with a second hot water inlet and a second hot water outlet, the water outlet is connected to one end of the backflow regulating valve and the first hot water inlet of the steam hot water heat exchanger through the first circulating pump, the water outlet is connected to the second hot water inlet of the flue gas hot water heat exchanger through the second circulating pump, and the second hot water outlet of the flue gas hot water heat exchanger is connected to the first hot water inlet of the steam hot water heat exchanger. The first hot water outlet and the other end of the backflow regulating valve are connected to the water inlet of the lactam heating system in parallel at point A, the steam source is connected to the steam inlet through the steam regulating valve, the first thermometer is arranged between the first hot water outlet and point A, and the second thermometer is arranged between the water inlet and point A. The controller is electrically connected to the first thermometer, the second thermometer, the first circulating pump, the second circulating pump, the backflow regulating valve and the steam regulating valve.

2. A lactam assisted hot water circulation system as claimed in claim 1 wherein: A pressure transmitter is further included and arranged between point A and the water inlet, and the controller is electrically connected to the pressure transmitter.

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